JPH0335850A - Mold for continuous casting - Google Patents

Abstract

PURPOSE:To restrain temp. raising of a mold, to make uniform the temp. distribution and to improve the quality of a cast slab by arranging through-holes parallel to slits in mold plates at positions in the mold corresponding to fitting positions of stud bolts and allowing cooling water to flow into the through-holes, too. CONSTITUTION:The slits 2 are arranged at the prescribed intervals in the mold plates 1 and backup plates 3 are attached to the plates 1 and the plates are fixed with the stud bolts 4. The plates 1 are cooled by allowing the cooling water to flow into the slits 2. Then, by increasing thickness of the mold plates 1, shortage of strength caused by arrangement of the through-holes 6 is eliminated and also length of the slits 2 is lengthened and the through-holes 6 are arranged parallel to the slits 2 at position in the plates 1 corresponding to the fitting positions of the stud bolts 4, and the cooling water flows into the through-holes 6, too. By this method, the mold for continuous casting with the improvement of cooling facility improved, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a continuous casting mold that lowers the surface temperature of a mold plate and achieves uniform temperature distribution.

(B) Prior art Typical examples of conventional continuous casting equipment are shown in Figures 5 to 8. Cooling of the mold constituting the conventional continuous casting equipment for steel is as shown in Figures 6 and 7. This is done by passing cooling water through slits 2 provided in the vertical direction on the back side of the mold plate 1, which constitute the long and short sides of the mold 10.

The surface of the mold plate 1 that comes into contact with the molten steel 5 is plated for wear resistance, and the mold plate 1 itself is made of copper or copper alloy, which has good thermal conductivity.

Further, as shown in FIG. 5, the mold plate 1 is fixed to the backup frame 3 with stud bolts 4.

By the way, in recent continuous casting technology, high-temperature slabs and high-speed casting are desired in order to achieve direct connection with hot rolling.

However, as high-speed casting technology is developed, the heat load on continuous casting molds, especially near the meniscus, increases.
Due to increased heat load, plating peels off and mold life decreases.
Breakouts and slab quality problems (cracks such as vertical cracks) were occurring due to thermal deformation. It is the stand bolt portion that poses a problem due to thermal deformation of the mold. In other words, the surface temperature rises at the stud bolt portion, and the elongation (deformation) at the bolt portion becomes maximum at the center with the bolt portion as the fixed end, causing plating to peel off due to movement of the short side during width change.

FIG. 8 shows images of plating peeling A and deformation of the mold plate 1.

In this way, the thermal deformation of the mold largely depends on the mold structure, and therefore, the slit depth was changed (Utility Model Publication No. 60-748).
(Japanese Utility Model Publication No. 59-85649), or by eliminating stud bolts and providing slits at equal intervals (Japanese Utility Model Publication No. 59-85649).
However, such a method cannot be said to be an optimal cooling method in terms of the mold life and the tightening force between the mold plate and the backup frame.

(c) Problems to be solved by the present invention The problems to be solved by the present invention are to reduce mold life by increasing the slit depth, and to improve cooling performance by eliminating stud bolts and making the slits evenly spaced. To provide a continuous casting mold which can solve the problem of a decrease in the tightening force between a mold plate and a backup frame due to this problem, and which can improve cooling capacity.

(d) Means for Solving the Problems In the continuous casting mold of the present invention, slits are provided in a mold plate at predetermined intervals, a backup frame is placed on the plate and fixed with stud bolts, and cooling water is allowed to flow through the slits. In the continuous casting mold for cooling the grate, the thickness of the plate is increased, the length of the slit is lengthened, and a through hole is provided in the grate parallel to the slit corresponding to the stud bolt mounting position, The above problem is solved by means of flowing cooling water also into the through holes.

(E) Function The mold plate and backup frame are interconnected by stud bolts.

However, because of this bolt, a cooling slit cannot be provided at that location, so in the mold of the present invention, a through hole is provided in the mold plate at the front side of the stud bolt to serve as a substitute for the slit.

(F) Embodiment An embodiment of the continuous casting mold 10a of the present invention will be described with reference to FIGS. 1 to 4.

The continuous casting mold 10a of the present invention includes a mold plate 1
Slits 2 are provided at predetermined intervals in the mold plate 1, a backup frame 3 is placed on the plate 1, and it is fixed with stud bolts 4.
This is a continuous casting mold for cooling. mold plate 1
The thickness T is increased, the length of the slit 2 is increased, a through hole 6 is provided in the plate 1 parallel to the slit 2 corresponding to the mounting position of the stud bolt 4, and cooling water is also allowed to flow through the through hole 6.

As best shown in FIG. 2, it is preferable that the upper edge of the slit 2 and the upper edge of the through hole 6 substantially coincide with each other, in order to make the cooling capacity uniform. Therefore, the length of the slit 2 becomes larger than that of the conventional one. It is preferable to insert a spacer 7 at the lower edge of the slit 2 in order to prevent an increase in the cross-sectional area due to an increase in the length L and to ensure the cooling water flow rate at the same flow rate9.The thickness T of the mold plate 1 is made larger than that of the conventional one. Therefore, the lack of strength caused by providing the through hole 6 is solved.

The state of temperature distribution near where the stud bolt 4 is installed is shown in the third diagram.
In the mold of the present invention shown in the figure, the temperature is clearly lower than that of the conventional mold. Furthermore, the temperature of the stud bolt portion is reduced to the same temperature as the other swant portions, and the mold grate surface temperature is made uniform.

Moreover, this tendency is the same even when the distance is away from the stud bolt 4 (Fig. 4). , it is possible to improve the quality of slabs.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a part of a continuous casting mold of the present invention, Fig. 2 is a cross-sectional view of a part of a copper plate used in the mold of the present invention, and Fig. 3 is a cross-sectional view of a part of a copper plate used in the mold of the present invention. An explanatory diagram showing. FIG. 4 is a graph showing the cooling effect of the mold of the present invention, FIG. 5 is a longitudinal cross-sectional view of a conventional mold, and FIG. 6 is a cross-sectional view of a part of a copper plate used in the conventional mold. FIG. 7 is a longitudinal sectional view of a part of a conventional mold, and FIG. 8 is a perspective view of a meniscus within the mold. 1: Mold plate 2 Nislit 3; Backup frame 4: Stud bolt 5; Molten steel 6: Through hole
7: Spacer 10.10a: Mold
L slit length W slit width T: mold plate thickness

Claims (1)

[Claims] In a continuous casting mold in which slits are provided at predetermined intervals in a mold plate, a backup frame is placed on the plate and fixed with stud bolts, and the plate is cooled by flowing cooling water through the slits, the thickness of the plate is increased, A continuous casting mold characterized in that the length of the slit is increased, a through hole is provided in the plate parallel to the slit corresponding to the stud bolt mounting position, and cooling water is also allowed to flow through the through hole.